Drawout switchgear apparatus



Dec. 15, 1959 Filed Aug. 24, 1956 5 Sheets-Sheet 1 Fig.|

. W|TNESSES= M INVENWR M Q yron A. OSI

TX BY ATTORNEY 1959 M. A. WASHIL 2,917,677

DRAWOUT SWITCHGEAR APPARATUS Filed Aug. 24, 1956 3 Sheets-Sheet 2 Dec.15, 1959 M. A. WASHIL DRAWOUT SWITCHGEAR APPARATUS 3 Sheets-Sheet 3Filed Aug. 24, 1956 United States Patent DRAWOUT SWITCHGEAR APPARATUSMyron A. Washil, Swissvale, Pa., assiguor to Westinghouse ElectricCorporation, East Pittsburgh, Pa., a corporation of PennsylvaniaApplication August 24, 1956, Serial No. 606,039

2 Claims. (Cl. 317-99) My invention relates, generally, to switchgearapparatus and, more particularly, to metal-enclosed switchgear of thedrawout type wherein apparatus units are withdrawable horizontally fromthe housings in which they are enclosed.

In certain applications for switchgear, for example, when it isnecessary to provide for connecting a transformer to one or the other oftwo main power circuits, .drawout fuse assemblies or units may beutilized. The fuses are mounted on trucks or carriages disposed inseparate compartments and provision is made for preventing both unitsfrom being connected at the same time.

An object of my invention is to provide mechanical interlocking meansfor two switchgear units of the drawout type which will prevent bothunits from being connected simultaneously.

Another object of my invention is to prevent access to a switchgearcompartment while apparatus within the compartment is energized.

A further object of my invention is to provide for interlockingswitchgear apparatus units which are located remotely from each other.

A more general object of my invention is to provide a mechanicalinterlocking system for switchgear apparatus units of the drawout typewhich shall be simple and efficient in operation and which may beeconomically manufactured and installed.

Other objects of my invention will be explained fully hereinafter orwill be apparent to those skilled in the art.

In accordance with one embodiment of my invention, each one of twocompartments which contain disconnect fuses of the drawout type isprovided with a compartment door for gaining access to the fuse and anoperating door for moving the carriage which supports the fuses. Thedoors are so hinged that the operating door can be opened independentlyof the compartment door, but the compartment door cannot be openedwithout opening the operating door to disconnect the fuses. Aninterlocking rod is actuated by one operating door to prevent both fuseassemblies from being connected at the same time. Key operated locksinterlock the fuse assemblies with a circuit breaker located remotelyfrom the fuse compartments.

For a better understanding of the nature and objects of my invention,reference may be had to the following detailed description, taken inconjunction with the accompanying drawings, in which:

Figure l is 'a view, partly in side elevation and partly in section, ofa portion of a switchgear structure embodying the principal features ofmy invention;

Fig. 2 is a view, partly in front elevation and partly in section, takenalong the line II-II in Fig. 1;

Fig. 3 is an enlarged view, in front elevation, of a portion of theswitchgear structure, the operating doors being in opposite positionsfrom those shown in Figs. 1 and 2;

Fig. 4 is an enlarged view, in left side elevation, of the structureshown in Fig. 3;

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Fig. 5 is an enlarged view, in right side elevation, of the structureshown in Fig. 3;

Fig. 6 is an enlarged detail view, in section, of a hinge for one of theoperating doors, and

Fig. 7 is an enlarged detail view, in section, of a hinge for one of thecompartment doors.

Referring to the drawings, and particularly to Figs. 1 and 2, theportion of a switchgear structure 10 shown therein, is divided into twocompartments 11 and 12. The structure 10 may be of the usualconstruction comprising angle frame members 13 which may be weldedtogether and to which sheet metal plates 14 may be attached to form ametal enclosure for housing switchgear apparatus. The compartment 11 isprovided with a compartment door 15 for gaining access to the apparatuswithin the compartment. Likewise, the compartment 12 is provided with adoor 16 for gaining access to the apparatus within the compartment. Thecompartments 11 and 12 are provided with additional operating doors orcarriage moving means 17 and 18, respectively. The operation of thedoors 15, 16, 17 and 18 will be described more fully hereinafter.

As explained hereinbefore, it is frequently desirable to provide forenergizing a-transformer or other power translating device from eitherone of two sources of power. In order to do this, it is necessary toprovide switching apparatus for selectively connecting the transformeror other device to one or the other of the two sources of power and alsofor preventing the transformer from being connected to both sources atthe same time.

In the interest of safety, it is also desirable to prevent an operatoror other person from coming in contact with electrical apparatus whichis energized. In the present structure, current-limiting fuses of thedrawout type are utilized as protective devices to protect thetranslating device against excessive amounts of current and they are somounted in the housing 10 that only one :set of fuses can be connectedat a time. Also, access cannot be gained to either compartment while thefuses within the compartment are energized.

As shown in Figs. 1 and 2, the fuse assembly in compartment 11 comprisesa plurality of fuses 21 which are mounted in fuse clips 22 of the usualtype. The clips 22 are supported by insulating members 23 which aremounted upon a bracket 24. The bracket 24 is part of a movable truck orcarriage 25 supported by rollers 26 which run upon rails 27 attached toa bottom plate 28 of the compartment 11.

One terminal of each fuse 21 is electrically connected to a contactmember 31 which is disposed to engage a contact member 32 when the truck25 has been moved inwardly in the compartment 11. The contact member 32is supported by an insulating member 33 secured to the back wall 14 ofthe housing structure 10. As shown, a power conductor 34 may beconnected to the contact member 32.

The lower terminal of each fuse 21 is electrically connected to anothercontact member 31 which engages another contact member 32 mounted on aninsulating member 33. A conductor 35 may be connected to the contactmember 32. Thus, when the truck 25 is moved inwardly in the compartment11 to cause all of the contact members 31 to engage their cooperatingcontact members 32, electrical circuits are established through thefuses 21. The conductors 34 and 35 may be connected to the proper powerconductors by connections made externally of the housing 10.

When the truck 25 is in its connected position, the truck frame isgrounded through a contact member 36 which engages a contact member 37connected to the bottom plate 28 of the switchgear structure. When thetruck 25 is in its disconnected position, the fuses are grounded througha contact member 38 which engages a contact member 39 attached to one ofthe angle members 13 of the switchgear structure.

The fuse assembly in compartment 12 is similar to the fuse assembly incompartment '11. The fuse'assernbly in compartment 12 comprises aplurality of fuses 41 which are mounted in fuse clips 42. The clips 4-2are supported by insulators 43 which are mounted upon a bracket 44. Thebracket 44 is part of a truck or carriage 45 supported by rollers 16which run upon rails 4-7 attached to a bottom plate 48 of thecompartment 12.

The terminals of the fuses are connected to contact members 51 which aredisposed to engage contact members 52 when the truck 45 is movedinwardly into the compartment 12. The contact members 52 are mountedupon insulators 53 secured to the wall 14 of the housing structure 18.Power conductors 54 and 55 are connected to the upper and lowerterminals 53, respectively. The conductors 54 and 55 may be connected toexternal power conductors.

The truck 25 may be moved in the compartment 11 by means of a pair oflinks 56 which are connected to the truck frame by pins 57. One end ofeach link 56 is pivotally connected to a bracket 58 by means of a pin59. The brackets 58 are secured to the carriage moving means oroperating door 17. When the door 17 is closed, the brackets 58 extendthrough openings 61 provided in the compartment door 15.

The truck 45, which is shown in its disconnected position, may be movedin the compartment 12 by means of a pair of links 66 which are attachedto the truck frame by pins 67. The outer ends of the links 66 areattached to brackets 68. The brackets 68 are secured to the carriagemoving means or operating door 18. Openings 71 are provided in thecompartment door 16 for the links 66 and the brackets 68.

As shown most clearly in Fig. 7, the compartment door is hinged to anangle member 72 of the switchgear structure by means of a hinge 73. Asshown in Fig. 6, the operating door 17 is hinged to the compartment door15 by means of a hinge 74 which is attached to a bar 75 secured to thecompartment door 15. The hinges 73 and 74 are coaxially disposed. Thecompartment door 16 and the operating door 18 are mounted in the samemanner as the doors 15 and 17 by means of hinges 73 and 74.

Since the carriage moving means or operating door for each compartmentis mounted on the compartment door for that compartment, the compartmentdoor cannot be opened to gain access to the apparatus in the compartmentwithout opening the operating door. Since the operating door isconnected to the truck or carriage in its compartment, access to theapparatus in the com partment cannot be gained without withdrawing thecarriage to its disconnected position, thereby deenergizing the fusesand grounding them through the grounding contacts 38 and 39. Thus, thepossibility of any person coming in contact with energized apparatuswithin either compartment is precluded.

As shown in Fig. 1, the truck in the compartment 11 is in the connectedposition and the truck 45 in the compartment 12 is in the disconnectedposition. The truck 25 may be moved to the disconnected position byopening the operating door 17 by means of a handle 70. Thus, both trucksmay be in the disconnected position at the same time and the compartmentdoors 15 and 16 may be opened to gain access to the fuses inside thecompartment.

However, the truck 45 in the compartment 12 cannot be moved to theconnected position while the truck 25 in compartment 11 is in theconnected position. An interlocking rod 76, which is slidab y mounted inbrackets 77 and 78 attached to a filler plate 79 in the switchgearstructure, is disposed to engage a bracket 85 secured to the operatingdoor 17 as seen in Fig. 2. The lower end of the interlocking bar 76 isconnected to a pin 82 by means of a link 83. The pin 82 is secured tothe operating door 18. Thus, the door 18 is prevented from being closedby the upper end of the interlocking rod 76 engaging the bracket 85 onthe door 17. The effective length of the interlocking rod 76 may beadjusted by means of a threaded nipple 84 on the lower end of the rod76.

If it is desired to move the truck 45 to the connected position, thetruck 25 must first be withdrawn to the disconnected position.

As shown in Figs. 3 and 4, the upper end of the interlocking rod 76 isfree to pass a bracket 85 secured to the operating door 17 when the door17 is in the open position. Thus, the operating door 18 may be closed tomove the truck 45 to the connected position.

However, the door 17 cannot be closed to move the truck 25 to theconnected position while the truck 45 is in the connected positionbecause the bracket 85 will strike the interlocking rod 76 to preventclosing the operating door 17. Therefore, it is necessary to open thedoor 18 to disconnect the truck 45 and lower the interlocking rod 76 tothe position shown in Fig. 1 before the operating door 17 can be closedto move the truck 25 to the connected position.

Accordingly, it is apparent that both sets of fuses cannot be in theconnected position at the same time. As previously explained, both setsof fuses can be in the disconnected position at the same time. As alsopreviously explained, it is impossible to open either one of thecompartment doors without opening the operating door for thecorresponding compartment to disconnect the fuses in that compartment.

As shown in Figs. 3 and 5, key interlocks 86 and 87 may be provided toprevent the trucks which carry the fuses from being moved to or from theconnected position while the disconnecting contact members areenergized. A bolt 88 on the lock 86 is in a position to engage a bracket89 on the operating door 17 to prevent closing the door 17 to move thetruck 25 to the connected position. The key for unlocking the lock 86may be obtained from a circuit breaker (not shown) which controls theenergization of the circuit which energizes the fuses 21. This key canbe obtained to unlock the lock 86 only when the circuit breaker is opento deenergize the fuses 21.

Likewise, a bolt 91 on the lock 87 is disposed to engage a bracket 92secured to the operating door 18, thereby preventing the opening of thedoor 18 to disconnect the fuses 41. The key for unlocking the lock 87may be obtained from a circuit breaker which controls the energizationof the fuses 41 only when the circuit breaker is open. Thus, the contactmembers 31 and 51 for the fuses 21 and 41, respectively, cannot beconnected or disconnected while carrying current.

From the foregoing description, it is apparent that I have provided amechanical interlocking system for preventing two apparatus units of thedrawout type from being in the connected position at the same time.However, the interlocking system does not prevent both units from beingin the disconnected position at the same time. Furthermore, thepossibility of a person coming in contact with either one of theapparatus units while energized is precluded. Also, neither one of theunits can be moved to or from the connected position while thedisconnecting contact members for the units are energized.

Since numerous changes may be made in the abovedescribed constructionand different embodiments of the invention may be made without departingfrom the spirit and scope thereof, it is intended that all the mattercontained in the foregoing description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

I claim as my invention:

1. In a switchgear structure, in combination, a pair of compartments,disconnect apparatus in each compartment, a movable carriage in eachcompartment for sup porting the disconnect apparatus, an operating doorfor each compartment, link means connecting each carriage to theoperating door for the compartment containing the carriage, acompartment door for each compartment, the operating door for eachcompartment being openable Without opening the compartment door for thesame compartment, the compartment door for each compartment beingunopenable Without opening the operating door for the same compartment,the compartment door for each compartment being closable Without movingthe operating door for the same compartment, an interlocking rodslidably mounted on the switchgear structure, and a link continuouslyconnecting said rod to one of said operating doors, said rod beingactuated bysaid one operating door to engage the other operating door toprevent both operating doors from being closed at the same time.

2. In a switchgear structure, in combination, a pair of compartments,disconnect apparatus in each compartment, a movable carriage in eachcompartment for supporting the disconnect apparatus, an operating doorfor each compartment, link means connecting each carriage to theoperating door for the compartment containing the carriage, acompartment door for each compartment,

the operating door for each compartment being openable without openingthe compartment door for the same compartment, the compartment door foreach compartment being unopenable without opening the operating door forthe same compartment, said compartment doors being closable withoutmoving the operating doors, an interlocking rod slidably mounted on theswitchgear structure, a link continuously connecting said rod to one ofsaid operating doors, said rod being actuated by said one operating doorto engage the other operating door to prevent both operating doors frombeing closed at the same time, and said rod being disposed to permitboth operating doors and both compartment doors to be opened at the sametime.

References Cited in the file of this patent UNITED STATES PATENTS1,575,001 Randall Mar. 2, 1926 1,658,913 Ansingh Feb. 14, 1928 2,156,672Allen May 2, 1939 2,363,364 Rugg Nov. 21, 1944 2,443,664 Rothfus June22, 1948 2,504,876 Pringle Apr. 18, 1950 2,573,485 Pifke Oct. 30, 19512,689,293 Claybourn Sept. 14, 1954 2,795,739 Wood June 11, 1957

